commit d221938c049f4845da13c8593132595a6b9222a8
author Gautham R Shenoy <ego@in.ibm.com> Fri Jan 25 21:08:01 2008 +0100
committer Ingo Molnar <mingo@elte.hu> Fri Jan 25 21:08:01 2008 +0100
tree 8eae6c7095a3d7d31d7435befc30019540a4d13e
parent 6b2d7700266b9402e12824e11e0099ae6a4a6a79

cpu-hotplug: refcount based cpu hotplug

This patch implements a Refcount + Waitqueue based model for
cpu-hotplug.

Now, a thread which wants to prevent cpu-hotplug, will bump up a global
refcount and the thread which wants to perform a cpu-hotplug operation
will block till the global refcount goes to zero.

The readers, if any, during an ongoing cpu-hotplug operation are blocked
until the cpu-hotplug operation is over.

Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Paul Jackson <pj@sgi.com> [For !CONFIG_HOTPLUG_CPU ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>